Fly-eye lens and illumination optical device

ABSTRACT

A fly-eye lens includes: an incident lens assemblage comprising a plurality of incident lenses that are aligned in a vertical direction, wherein each of the incident lenses has a quadrangular shape, wherein horizontal lens widths of the incident lens are the same, and wherein vertical lens widths of at least some of the incident lens are different from one another; and an emission lens assemblage comprising a plurality of emission lenses that are aligned in the vertical direction so as to be optically opposed to the incident lenses, wherein each of the emission lenses has a quadrangular shape, and wherein horizontal lens widths of the emission lenses lens are the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Japanese Application No.2018-184342, filed on Sep. 28, 2018, which is incorporated by referencein its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a fly-eye lens and an illuminationoptical device.

2. Description of Related Art

Recent years have seen numerous attempts to develop an ADB (adaptivedriving beam) as an applied product of a spatial light modulationelement such as an LCD (liquid crystal device), an LCOS (liquid crystalon silicon), a DMD (digital micromirror device) and the like. Aconventional illumination optical device includes a light source, anincident lens, and an emission lens. In the illumination optical device,at least one aperture of the incident lens has a shape smaller than ashape formed just on the illuminated surface. The plane distribution inthe illuminated surface is adjusted so that illuminance is higher aboutthe center of the illuminated surface and lower toward the periphery(see paragraph 0007 in JP 09-222581 A).

SUMMARY

In order to provide an uneven illumination distribution as in JP09-222581 A, the conventional illumination optical device requires aportion where adjacent ones of simple lenses are very different in sizein each of the incident lens and the emission lens. Hence, the emissionlens or the incident lens includes a great step height at the portionwhere adjacent ones of simple lenses are connected. That is, when anuneven illumination distribution is desired, the step height in theincident lens or the emission lens becomes great and manufacturingthereof becomes difficult.

An object of certain embodiments of the present disclosure is to providea fly-eye lens and an illumination optical device without a great stepheight despite lenses being configured to provide an uneven illuminationdistribution.

A fly-eye lens according to an embodiment of the present disclosureincludes: an incident lens assemblage having incident lenses of aquadrangular shape aligned in a vertical direction, the incident lensesbeing different from one another in a vertical lens width and the sameas one another in a horizontal lens width; and an emission lensassemblage having emission lenses of a quadrangular shape aligned in thevertical direction so as to be optically opposed to the incident lenses,the emission lenses being the same as one another in the horizontal lenswidth. The incident lenses have a dimension of the quadrangular shapeset so that a preset illumination region is attained by a group ofillumination ranges respectively illuminated with light from one or moreof the incident lenses in an illuminated surface, and have their lensvertices eccentrically positioned so as to supply light to the emissionlenses optically opposed to the incident lenses. The emission lenseshave a dimension of the quadrangular shape and their lens verticespositioned so that any of the plurality of illumination ranges formingthe illumination region is attained, and so that at least part of theillumination ranges are overlapped on each other.

A fly-eye lens according to another embodiment of the present disclosureincludes: an incident lens assemblage formed of first incident lenses ofa quadrangular shape and second incident lenses of a quadrangular shapeof which horizontal lens width is equivalent to a horizontal lens widthof the first incident lenses and of which vertical lens width is smallerthan a vertical lens width of the first incident lenses, the firstincident lenses and the second incident lenses being aligned in avertical direction and a horizontal direction with their horizontal lenswidth being the same in a vertical column; and an emission lensassemblage formed of first emission lenses of a quadrangular shapeoptically opposed to the first incident lenses and second emissionlenses of a quadrangular shape optically opposed to the second incidentlenses, the first emission lenses and the second emission lenses beingaligned in the vertical direction and the horizontal direction withtheir horizontal lens width being the same in a vertical column. Thefirst incident lenses have a dimension of the quadrangular shape set sothat a preset first illumination region is attained in an illuminatedsurface, and have their lens vertices positioned so as to supply lightto the first emission lenses optically opposed to the first incidentlenses. The second incident lenses have a dimension of the quadrangularshape set so that a second illumination region smaller in area than thefirst illumination region and being at least partially overlapped on thefirst illumination region in an illuminated surface, and have their lensvertices positioned so as to supply light to the second emission lensesoptically opposed to the second incident lenses. The first emissionlenses have a dimension of the quadrangular shape set and lens verticeseccentrically positioned so as to emit light in the first illuminationregion. The second emission lenses have a dimension of the quadrangularshape set and lens vertices positioned so as to emit light in the secondillumination region.

An illumination optical device according to another embodiment of thepresent disclosure includes: a first optical member disposed on anoptical path from a light source and configured to convert light fromthe light source to a substantially collimated light beam; a fly-eyelens configured to receive light from the first optical member and emitthe light with a desired gray scale distribution; a second opticalmember disposed on an optical path of the light from the fly-eye lens; alight modulation device configured to receive light from the secondoptical member and emit the light with its optical path changed; and aprojection lens configured to project the light from the lightmodulation device. The fly-eye lens is the above-described fly-eye lens.

The fly-eye lens according to certain embodiments of the presentdisclosure does not include a great step height despite an unevenillumination distribution of its lens configuration.

The illumination optical device according to certain embodiments of thepresent disclosure does not include a great step height despite lensesbeing configured to provide an uneven illumination distribution.Therefore the illumination optical device may be easily manufactured.For example, an illumination region suitable for a headlamp may beformed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically showing the relationshipbetween a fly-eye lens and an illumination region according to a firstembodiment.

FIG. 2 is a schematic side view of the fly-eye lens according to thefirst embodiment.

FIG. 3 is a perspective view schematically showing an optical opposingrelationship between second incident lenses and second emission lensesaccording to the first embodiment.

FIG. 4 is a schematic perspective view of the incident lens assemblageside of the fly-eye lens according to the first embodiment.

FIG. 5 is an enlarged schematic view of a region V in FIG. 1.

FIG. 6 is a perspective view schematically showing the emission lensside of the fly-eye lens according to the first embodiment.

FIG. 7 is a schematic enlarged view of a region VII in FIG. 6.

FIG. 8A is an explanatory illustration for describing the configurationof a first illumination region and a second illumination region providedby the fly-eye lens according to the first embodiment illuminating alight modulation part of a light modulation device.

FIG. 8B is an explanatory illustration for describing the relationship,in the second emission lenses of the fly-eye lens according to the firstembodiment, between emission 1st lens rows and a first range of thesecond illumination region.

FIG. 8C is an explanatory illustration for describing the relationship,in the second emission lens of the fly-eye lens according to the firstembodiment, between emission 2nd lens rows and a second range of thesecond illumination region.

FIG. 9A is an explanatory illustration schematically showing therelationship between light emitted in the horizontal direction of thefly-eye lens according to the first embodiment and the illuminationregion.

FIG. 9B is an explanatory illustration for describing the relationshipbetween light emitted from a first emission lens group of the fly-eyelens according to the first embodiment and an illumination position inthe horizontal direction of the light modulation part of the lightmodulation device.

FIG. 9C is an explanatory illustration for describing the relationshipbetween light emitted from an emission 1st lens group of a secondemission lens group in the fly-eye lens according to the firstembodiment and an illumination position in the horizontal direction ofthe light modulation part of the light modulation device.

FIG. 9D is an explanatory illustration for describing the relationshipbetween light emitted from an emission 2nd lens group of the secondemission lens group in the fly-eye lens according to the firstembodiment and an illumination position in the horizontal direction ofthe light modulation part of the light modulation device.

FIG. 10A is an explanatory illustration schematically showing, with someomissions, the relationship between light emitted in the verticaldirection of the fly-eye lens according to the first embodiment and anillumination region.

FIG. 10B is an explanatory illustration schematically showing therelationship between light emitted from the first emission lens in thevertical direction of the fly-eye lens according to the first embodimentand the first illumination region in the light modulation part of thelight modulation device.

FIG. 10C is an explanatory illustration schematically showing therelationship between light emitted from an emission 1st lens of thesecond emission lens in the vertical direction of the fly-eye lensaccording to the first embodiment and a first range of the secondillumination region in the light modulation part of the light modulationdevice.

FIG. 10D is an explanatory illustration schematically showing therelationship between light emitted from an emission 2nd lens of thesecond emission lens in the vertical direction in the fly-eye lensaccording to the first embodiment and a third range of the secondillumination region in the light modulation part of the light modulationdevice.

FIG. 11 is an explanatory illustration for describing the relationshipbetween emission 1st lens rows in a second emission lens of a fly-eyelens according to a variation and a first range of a second illuminationregion.

FIG. 12A is an explanatory illustration for describing the relationshipbetween light emitted from emission 1st lens rows in a second emissionlens of a fly-eye lens according to other variation and a first range ofa second illumination region.

FIG. 12B is an explanatory illustration describing the relationshipbetween light emitted from an odd numbered lens in any lens row in thesecond emission lens of the fly-eye lens according to other variationand the first range of the second illumination region.

FIG. 12C is an explanatory illustration describing the relationshipbetween light emitted from an even numbered lens in any lens row in thesecond emission lens of the fly-eye lens according to other variationand the first range of the second illumination region.

FIG. 13A is an explanatory illustration schematically showing the stateof a first illumination region and a second illumination region in anillumination region provided by the fly-eye lens according to othervariation illuminating a light modulation part of a light modulationdevice.

FIG. 13B is an explanatory illustration showing an illumination regionand a light illumination intensity distribution provided by the fly-eyelens according to the first embodiment illuminating the light modulationpart of the light modulation device.

FIG. 14A is a perspective view schematically showing other configurationof the fly-eye lens.

FIG. 14B is an explanatory illustration schematically showing otherconfiguration of the light illumination intensity distribution of theillumination region.

FIG. 14C is an explanatory illustration schematically showing otherconfiguration of the light illumination intensity distribution of theillumination region.

FIG. 15 is a perspective view schematically showing the wholeillumination optical device.

FIG. 16A is an explanatory illustration schematically showing theconfiguration in which a reflecting optical system is used as the firstoptical member in the illumination optical device.

FIG. 16B is an explanatory illustration schematically showing theconfiguration in which other reflecting optical system is used as thefirst optical member in the illumination optical device.

DETAILED DESCRIPTION

Embodiments of the present invention will be described below withreference to the drawings as appropriate. The embodiments describedbelow are merely examples for explaining the technical ideas of thepresent invention. However, the present invention is not limited to thedescribed embodiments unless otherwise specified. Furthermore, the size,positional relationship and the like of members shown in the drawingsmay be exaggerated for the sake of clarity. The description withreference to the drawings is given on the premise that, as an example,the top-bottom direction of the fly-eye lens is the Z-direction, thewidth direction of the fly-eye lens is the X-direction, and thethickness direction of the fly-eye lens is the Y-direction. The fly-eyelens has the incident lens assemblage on its front side.

Overview of Fly-Eye Lens and Illumination Region

As shown in FIGS. 1, 2, and 10A, a fly-eye lens 10 is configured toreceive light at incident lenses 11 a, and emit the light via emissionlenses 11 b so that the light attains a predetermined light illuminationintensity distribution in a predetermined illumination region. As shownin FIGS. 4 and 6, the fly-eye lens 10 includes a plurality of incidentlenses 11 a and a plurality of emission lenses 11 b aligned in thevertical direction (the Z-direction) and the horizontal direction (theX-direction) using a lens upper frame part 12, a lens lower frame part13, a lens left frame part 14, and a lens right frame part 15. As shownin FIGS. 2 and 3, the incident lenses 11 a and the emission lenses 11 bare disposed at positions optically opposed to each other, having thesize and the position of the lens vertices set for each illuminationregion. Note that, as an example, in the first embodiment, as to thedimension (size) of the incident lenses 11 a and the emission lenses 11b of the fly-eye lens 10, the incident lenses 11 a and the emissionlenses 11 b have the same horizontal lens width and three differentvertical lens widths.

As shown in FIG. 1, an illumination region EA of the fly-eye lens 10 isroughly set by a first illumination region E1 and a second illuminationregion E2. The illumination region EA is set to present a predeterminedlight illumination intensity distribution entirely or partially by thefirst illumination region E1 and the second illumination region E2. Thesecond illumination region E2 is set by a plurality of ranges, and thedescription is exemplarily given of the second illumination region E2set by two ranges, namely, a first range 1Eb and a second range 2Eb. Asshown in FIGS. 10A, 9B to 9D, the fly-eye lens 10 is formed having lensvertices TLb of the emission lenses 11 b eccentrically positioned sothat, as the lens groups are nearer to a lens surface center CL, theregions of light beams emitted from respective lens groups spread in theX-direction (the horizontal direction), and an overlapped regions formedby such regions at a region center HCL gradually becomes smaller. Thatis, a first emission lens group 11UL1 shown in FIG. 9B is disposedfarthest from the lens surface center CL, to emit light that is near tothe region center HCL. An emission 2nd lens group 11UL3 shown in FIG. 9Dis disposed nearest to the lens surface center CL, to emit lightincluding those far from the region center HCL in the horizontaldirection.

Note that, as shown in FIGS. 2 and 3, the incident lenses 11 a and theemission lenses 11 b being “optically opposed to each other” means thatthey are opposed to each other for causing light (BL) emitted from oneincident lens 11 a to become incident on one emission lens 11 b. In FIG.1, as to the first range 1Eb and the second range 2Eb of the secondillumination region E2, one light range Bw1 or one range Bw2 illuminatedwith light from one second emission lens 11 bB is represented by a solidline and a broken line. A solid line represents the entire first range1Eb consisting of two ranges Bw1 or the entire second range 2Ebconsisting of two ranges Bw2. The first illumination region E1 is alsorepresented as the range of a group of a first range 1Ea to a fifthrange 5Ea (the total illumination area) (see FIG. 8A).

As shown in FIG. 1, the first illumination region E1 and the secondillumination region E2 refer to regions set in the preset illuminationregion EA. The second illumination region E2 refers to a region that atleast is partially overlapped on the first illumination region E1, andthat is smaller in area than the first illumination region E1. As anexample, as shown in FIG. 8A, the first illumination region E1 is set asone region consisting of a plurality of illuminated ranges, namely, thefirst range 1Ea to the fifth range 5Ea. The second illumination regionE2 in the present embodiment is set as a plurality of regions and, as anexample, as a group of two regions.

That is, the second illumination region E2 consists of the first range(illumination range) 1Eb and the second range (illumination range) 2Eb.So long as at least one of the first range 1Eb and the second range 2Ebis partially overlapped on the first illumination region E1, the secondillumination region E2 may be set to partially project outward of theillumination region EA. The first range 1Eb and the second range 2Ebhave vertical symmetry with reference to the region center HCL in theX-direction of the illumination region EA. In the drawings, those linesrepresenting light, and lines representing a region, a range, a section,a subsection illuminated with light are provided merely for the sake ofeasier understanding, and do not actually exist. The description will beexemplarily given of a quadrangular-shaped lens, and the lens sizesubstantially means the dimension of the quadrangular shape (thehorizontal lens width and the vertical lens width).

Incident Lenses

In the following, with reference to FIGS. 1 to 8C, a description will begiven of the incident lenses 11 a.

The incident lenses 11 a are configured to receive light from a lightsource, and supply the light to the optically opposed emission lenses 11b. The incident lenses 11 a are quadrangular convex lenses that are thesame as one another in the horizontal lens width and different from oneanother in the vertical lens width. The incident lenses 11 a includefirst incident lenses 11 a 1 and second incident lenses 11 aA. Theincident lenses 11 a are arranged in a matrix (XZ-directions: horizontaland vertical directions) adjacent to one another, to form an incidentlens assemblage 11A. As shown in FIG. 2, when aligned, the incidentlenses 11 a present a wavy lens surface having lens vertices TLaconnected in the incident lens assemblage 11A. That is, the lensassemblage 11A has a curved wavy lens surface as seen in a side view inwhich, while being parallel to one another in the horizontal direction,an incident-side concave surface 11RA1 and incident-side convex surfaces11RA2, 11RA3 are continuous to one another in the vertical direction.

In the present embodiment, the incident lens assemblage 11A is providedwith the incident-side concave surface 11RA1 at the position of the lenssurface center CL in the vertical direction (the Z-direction). On theupper and lower sides of the incident-side concave surface 11RA1, theincident-side convex surfaces 11RA2, 11RA3 are formed. The incident-sideconcave surface 11RA1 and the incident-side convex surfaces 11RA2, 11RA3are formed in accordance with the height of the lens vertices TLa or theshape of the incident lenses 11 a.

In the incident lens assemblage 11A, the second incident lenses 11 aAare different from each other in the vertical lens width correspondingto respective illumination regions. The lenses with a smaller verticallens width are disposed nearer to the lens surface center CL. In theincident lens assemblage 11A, the vertical lens width of the lensesbecomes gradually greater from the lens surface center CL toward theupper and lower edges. Thus, in the incident lens assemblage 11A, theincident-side concave surface 11RA1 is formed at the portioncorresponding to the lens surface center CL. On the upper side relativeto the lens surface center CL, the incident-side convex surfaces 11RA2is formed. On the lower side relative to the lens surface center CL, theincident-side concave surface 11RA3 is formed.

First Incident Lenses

As shown in FIGS. 4 to 7, the first incident lenses 11 a 1 areconfigured to supply light to the first emission lenses 11 b 1 that emitthe light in the first illumination region E1. The first incident lenses11 a 1 are lenses of the same shape aligned in one or more rows. As anexample, from the upper level to the lower level in the incident lensassemblage 11A, the first incident lenses 11 a 1 are aligned in first tothird rows to form an incident 1st lens row 11N11 to an incident 3rdlens row 11N13. In the first incident lenses 11 a 1, the incident 1stlens row 11N11 to the incident 3rd lens row 11N13 are a first incidentlens group 11NL1. The first incident lens group 11NL1 is formed of thefirst incident lenses 11 a 1 of the same vertical lens width and thesame horizontal lens width being aligned in a plurality of rows in thepresent embodiment. The first incident lens group 11NL1 is disposed ateach of two locations that have horizontal symmetry with reference tothe lens surface center CL in the Z-direction.

In the present embodiment, each of the first incident lens groups 11NL1is a group of three rows of the incident 1st lens row 11N11 to theincident 3rd lens row 11N13 in which the first incident lenses 11 a 1 ofthe same size (dimension) are arranged. The first incident lens groups11NL1 are respectively disposed at the higher level and the lower level,to form part of the incident lens assemblage 11A. Each first incidentlens group 11NL1 have the lens vertices TLa eccentrically positioned soas to cause light from the first incident lenses 11 a 1 become incidenton the opposite first emission lenses 11 b 1. The size and eccentricityof the lens vertices TLa of the incident lenses 11 a are set so as tocause light to become incident on the optically opposed emission lenses11 b and to set the ranges of the illumination region. As an example, inthe first incident lens group 11NL1, each of the first incident lenses11 a 1 is a quadrangular convex lens. Accordingly, the first incidentlenses 11 a 1, which are convex lenses, have the lens vertices TLa setto allow light to become incident on the optically opposed firstemission lenses 11 b 1. As for the size of each first incident lens 11 a1, the vertical lens width and the horizontal lens width are designed toset the first illumination region E1. Note that, the first illuminationregion E1 corresponds to the total of overlapped and aligned similarshapes of the first incident lens 11 a 1. The vertical lens width andthe horizontal lens width of the incident lenses 11 a are reflected onilluminated region that is illuminated as a substantially similar shapeof the first incident lens 11 a 1 corresponding to the vertical regionsize and the horizontal region size. Note that, as shown in FIG. 1, inthe incident second lenses 11 aA, the incident 1st lenses 11 a 2 arereflected on an illuminated range Bw1 that is similar in the horizontallens width. In the incident second lenses 11 aA, the incident 2nd lenses11 a 3 are reflected on an illuminated range Bw2 that is similar in thehorizontal lens width.

Second Incident Lenses

The second incident lenses 11 aA are configured to supply light to thesecond emission lenses 11 bB that illuminate the second illuminationregion E2. Each of the second incident lenses 11 aA is a quadrangularconvex lens that is the same as the first incident lens 11 a 1 in thehorizontal lens width and smaller than the first incident lens 11 a 1 inthe vertical lens width. Preferably, the vertical lens width of thesecond incident lens 11 aA is 50% or less as great as the vertical lenswidth of the first incident lens 11 a 1. By virtue of the secondincident lenses 11 aA having the vertical lens width that is 50% or lessas great as that of the first incident lenses 11 a 1, numerous smallillumination regions can be set in the entire illumination region. Thisimproves flexibility in setting the light distribution of theillumination region. In the second incident lenses 11 aA, lens groupsdiffering from each other in the vertical lens width are alignedrespectively in rows so as to have horizontal symmetry with reference tothe lens surface center CL of the incident lens assemblage 11A. Thevertical lens width of the second incident lens 11 aA is designedcorresponding to the number of the first range 1Eb and the second range2Eb in the second illumination region E2.

As shown in FIGS. 4 and 5, as an example, in the case in which thesecond incident lenses 11 aA emit light separately in two ranges, thesecond incident lenses 11 aA are designed to have two different verticallens widths. In the present embodiment, the second incident lenses 11 aAinclude incident 1st lenses 11 a 2 and incident 2nd lenses 11 a 3. Thesecond incident lenses 11 aA are aligned in the horizontal direction toform each row. The incident 1st lenses 11 a 2 and the incident 2ndlenses 11 a 3 are each formed as a group of a preset number of lensrows. The group of the incident 1st lenses 11 a 2 and the group of theincident 2nd lenses 11 a 3 form a second incident lens group 11NLA. Thatis, the second incident lens group 11NLA includes, in the presentembodiment, an incident 1st lens group 11NL2 and an incident 2nd lensgroup 11NL3. Accordingly, the second incident lens group 11NLA is formedof, excluding the first incident lens group 11NL1 formed of the firstincident lenses 11 a 1, the second incident lenses 11 aA that is acluster of lens groups differing from each other in the vertical lenswidth.

Incident 1st Lenses

The incident 1st lenses 11 a 2 are formed having the lens vertices TLaeccentrically positioned so as to cause light to become incident on theemission 1st lenses 11 b 2 of the optically opposed second emissionlenses 11 bB. The incident 1st lenses 11 a 2 are smaller in the verticallens width than the first incident lenses 11 a 1, and greater in thevertical lens width than the incident 2nd lenses 11 a 3. In the presentembodiment, the incident 1st lenses 11 a 2 are the same in size andaligned in four rows, namely, an incident 1st lens row 11N21 to anincident 4th lens row 11N24. The incident 1st lens row 11N21 to theincident 4th lens row 11N24 form an incident 1st lens group 11NL2 inwhich all the incident 1st lenses 11 a 2 in the four rows have the samesize.

The incident 1st lenses 11 a 2 are aligned respectively continuous tothe upper and lower first incident lens groups 11NL1 of the firstincident lenses 11 a 1. That is, the incident 1st lens row 11N21 to theincident 4th lens row 11N24 are formed as an incident 1st lens group11NL2 at each of two locations, that is, one from the higher level tothe lower level in the incident lens assemblage 11A, and other from thelower level to the higher level in the incident lens assemblage 11A. Inthe present embodiment, the incident 1st lens groups 11NL2 are formed tobe continuous to the first incident lens groups 11NL1 so as to havehorizontal symmetry with reference to the lens surface center CL.

The lens size of the incident 1st lenses 11 a 2 is designed so that thefirst range 1Eb in the second illumination region E2 is set by one ormore lenses. In the present embodiment, the first range 1Eb is formed byranges respectively illuminated by at least two incident 1st lenses 11 a2. The first range 1Eb is set to be an overlapped region (a group ofregions) of respective illumination ranges of the incident 1st lenses 11a 2 in four rows of the incident 1st lens row 11N21 to the incident 4thlens row 11N24. Note that, the first range 1Eb in FIG. 1 is the total ofa plurality of aligned shapes each substantially similar to one lenssize of the incident 1st lenses 11 a 2. That is, in the presentembodiment, the first range 1Eb is formed as a maximum area illuminatedby light from two incident 1st lenses 11 a 2. Therefore, a range of theilluminated area by one incident 1st lens 11 a 2 has the shapesubstantially similar to the lens size. The same holds true for othersecond range 2Eb, which will be described later.

Incident 2nd Lenses

The incident 2nd lenses 11 a 3 are formed having the lens vertices TLaeccentrically positioned so as to cause light to become incident on theemission 2nd lenses 11 b 3 of the optically opposed second emissionlenses 11 bB. The incident 2nd lenses 11 a 3 are smaller in the verticallens width than the incident 1st lenses 11 a 2. The incident 2nd lenses11 a 3 are the same in size and aligned in six rows, namely, an incident1st lens row 11N31 to an incident 6th lens row 11N36.

The incident 1st lens row 11N31 to the incident 6th lens row 11N36 formthe incident 2nd lens group 11NL3 in which all the incident 2nd lenses11 a 3 in the six rows have the same size. The incident 2nd lenses 11 a3 are aligned respectively continuous to the upper and lower incident1st lens groups 11NL2 of the incident 1st lenses 11 a 2.

That is, the incident 1st lens row 11N31 to the incident 6th lens row11N36 are formed as the incident 2nd lens group 11NL3 at each of twolocations, that is, one from the higher level to the lower level in theincident lens assemblage 11A, and other from the lower level to thehigher level in the incident lens assemblage 11A. In the presentembodiment, the incident 2nd lens groups 11NL3 are formed to becontinuous to the incident 1st lens groups 11NL2 so as to havehorizontal symmetry with reference to the lens surface center CL. Thatis, the incident 1st lens row 11N31 to the incident 6th lens row 11N36are formed as two continuous groups at the center of the incident lensassemblage 11A.

The size of the incident 2nd lenses 11 a 3 is designed so that thesecond range 2Eb in the second illumination region E2 is set by one ormore lenses. The second range 2Eb is formed by a maximum rangeilluminated by two incident 2nd lenses 11 a 3. More specifically, thesecond range 2Eb is set to be an overlapped region (a group of regions)of respective illumination ranges of six rows, namely, the incident 2ndlens row 11N31 to the incident 6th lens row 11N36. Note that, the secondrange 2Eb in FIG. 1 is the total of a plurality of aligned shapes eachsubstantially similar to one lens size of the incident 2nd lenses 11 a3.

While it has been described that the incident lenses 11 a have the lensvertices TLa eccentrically positioned so as to cause light to becomeincident on the emission lenses 11 b, the eccentric positioning referredto herein also includes positioning the lens vertices TLa so as tocoincide with the optical axes of the lenses. That is, the incidentlenses 11 a are just required to have the lens vertices TLa formed so asto be capable of supplying light to the opposed emission lenses 11 b.

Emission Lenses

Next, with reference to FIGS. 1 to 10D, a description will be given ofthe emission lenses 11 b. In the present embodiment, in an emission lensassemblage 11B, the emission lenses 11 b all have the same size(dimension) as to the horizontal lens width.

The emission lenses 11 b are configured to receive light from theincident lens 11 a, and emit the light to illumination regions in apreset direction. In the present embodiment, the emission lenses 11 bare quadrangular convex lenses that are the same as one another in thehorizontal lens width and different from one another in the verticallens width. The emission lenses 11 b are arranged in a matrix (theX-direction and the Z-direction) at positions optically opposed to theincident lenses 11 a to receive light therefrom. The emission lenses 11b include first emission lenses 11 b 1 and second emission lenses 11 bB.By the first emission lenses 11 b 1 and the second emission lenses 11 bBof the emission lenses 11 b being aligned adjacent to one another, theemission lens assemblage 11B is formed.

Note that, as shown in FIG. 2, when aligned, the emission lenses 11 bpresent a wavy lens surface having lens vertices TLb connected in theemission lens assemblage 11B. That is, the lens assemblage 11B has acurved wavy lens surface as seen in a side view in which, while beingparallel to one another in the horizontal direction (the X-direction:the row direction), an emission-side convex surface 11RB1 andemission-side concave surfaces 11RB2, 11RB3 are continuous to oneanother in vertical direction. The emission lens assemblage 11B isformed corresponding to the height of the lens vertices TLb and the lensshape, and parallel to the incident lens assemblage 11A.

That is, in the emission lens assemblage 11B, the portion correspondingto the lens surface center CL is the emission-side convex surface 11RB1.On the upper side relative to the emission-side convex surface 11RB1,the emission-side concave surface 11RB2 is formed. On the lower siderelative to the lens surface center CL, the emission-side concavesurface 11RB3 is formed.

In the emission lens assemblage 11B, the second emission lenses 11 bBare different in the vertical lens width for each lens groupcorresponding to illumination regions. The second emission lenses 11 bBof which vertical lens width is smaller are disposed nearer to the lenssurface center CL.

In the emission lens assemblage 11B, the vertical lens width becomesgradually greater from the lens surface center CL toward the upper andlower edges. That is, in the emission lens assemblage 11B, the verticallens width is set to have horizontal symmetry with reference to the lenssurface center CL. Note that, the emission lenses 11 b are all the sameas one another in the horizontal lens width in the emission lensassemblage 11B. Furthermore, the emission lenses 11 b are also the samein the horizontal lens width to the incident lenses 11 a.

First Emission Lenses

The first emission lenses 11 b 1 are configured to receive light fromthe first incident lenses 11 a 1 and emit the light in the firstillumination region E1. The first emission lenses 11 b 1 are lenses ofthe same shape aligned in one or more rows. As an example, from thehigher level to the lower level in the emission lens assemblage 11B, thefirst emission lenses 11 b 1 are aligned in the first to third rows toform an emission 1st lens row 11U11 to an emission 3rd lens row 11U13.In the first emission lenses 11 b 1, the emission 1st lens row 11U11 tothe emission 3rd lens row 11U13 are the first emission lens group 11UL1.The first emission lens group 11UL1 is formed of first emission lenses11 b 1, which are quadrangular convex lenses, of the same vertical lenswidth and the same horizontal lens width arranged in a plurality of(three) rows in the present embodiment. The first emission lens group11UL1 is disposed so as to oppose to the first incident lens group11NL1. The first emission lens group 11UL1 is disposed at each of twolocations that have horizontal symmetry with reference to the lenssurface center CL in the Z-direction.

First Emission Lenses and Corresponding Illumination Region

Each first emission lens group 11UL1 has the lens vertices TLbpositioned so as to cause light from the first incident lenses 11 a 1 tobe emitted in the plurality of ranges (see FIG. 8A) in the firstillumination region E1. In the first emission lens group 11UL1, the lensvertex TLb is different for each of the first to third rows of the firstemission lenses 11 b 1.

As shown in FIGS. 6 and 8A, an emission 1st lens row 11U11 that is thefirst row in the first emission lens group 11UL1 has the lens verticesTLb (see FIG. 3) set to emit light in the central third range 3Ea in thefirst illumination region E1. That is, the emission 1st lens row 11U11has the lens vertices TLb set so that light from an odd numbered firstemission lens 11 b 1 d and light from an even numbered first emissionlens 11 b 1 a both illuminate the same third range 3Ea in the firstillumination region E1. The odd numbered first emission lens 11 b 1 isdenoted by the reference character “11 b 1 d” with a suffix “d”, and theeven numbered first emission lens 11 b 1 is denoted by “11 b 1 a” with asuffix “a”.

The emission 2nd lens row 11U12 that is the second row in the firstemission lens group 11UL1 has the lens vertices TLb set to emit lightfrom the odd numbered first emission lens 11 b 1 d in the second range2Ea in the first illumination region E1, and to emit light from the evennumbered first emission lens 11 b 1 a in the fourth range 4Ea in thefirst illumination region E1.

The emission 3rd lens row 11U13 that is the third row in the firstemission lens group 11UL1 has the lens vertices TLb set to emit lightfrom the odd numbered first emission lens 11 b 1 d in the fifth range5Ea in the first illumination region E1, and to emit light from the evennumbered first emission lens 11 b 1 a in the first range 1Ea in thefirst illumination region E1.

In this manner, with the first emission lens group 11UL1, the firstillumination region E1 is set as the total of the illumination rangesthat are different for each lens row and overlapped on one another inthe central region in the first illumination region E1. Accordingly, inthe whole first illumination region E1, the light illumination intensitydistribution is higher at the center and is lower at the periphery. Theillumination ranges in the first illumination region E1 may be differentbetween an odd numbered lens and an even numbered lens belonging to thesame lens row in the first emission lens group 11UL1. Alternatively, thelens vertices TLb may be set for each lens row, that is, theillumination range in the first illumination region E1 may be the samebetween an odd numbered lens and an even numbered lens belonging to thesame lens row. Thus, with the first emission lens group 11UL1, the lightillumination intensity distribution of the illumination region is seteasier. The first emission lenses 11 b 1 that are quadrangular convexlenses are all the same in the horizontal lens width and the verticallens width in the first emission lens group 11UL1, with the lensvertices TLb eccentrically positioned, thereby illuminating differentregions in the first illumination region E1 depending on the directionsin which light is emitted. As for the second illumination region E2,similar to the above-described first illumination region E1, theillumination region is formed by a plurality of ranges illuminated bylight from the lenses arranged in rows. Details thereof will be givenlater.

As shown in FIGS. 6, 7, 10A, and 10B, in the fly-eye lens 10, the firstemission lens group 11UL1 is formed at each of two locations so as tohave symmetry with reference to the lens surface center CL. Thus, thefly-eye lens 10 forms the first illumination region E1 (1EA) by lightbeams from the first emission lens groups 11UL1 of these two locations.As shown in FIG. 9B, in the fly-eye lens 10, the lens vertices TLb areset so that the lenses nearer to the lens surface center CL (see FIG.10A) provide a wider illumination region width in the horizontaldirection. Because each first emission lens group 11UL1 illuminating thefirst illumination region E1 is the farthest from the lens surfacecenter CL, the first emission lens group 11UL1 has the lens vertices TLbset so that corresponding illumination region width is the nearest tothe region center HCL.

Second Emission Lenses

Next, the second emission lenses 11 bB are configured to receive lightfrom the second incident lenses 11 aA and emit the light in the firstrange 1Eb to the second range 2Eb in the second illumination region E2.Each of the second emission lenses 11 bB is a quadrangular convex lensthat is the same as the first emission lens 11 b 1 in the horizontallens width and smaller than the first emission lens 11 b 1 in thevertical lens width. Preferably, the vertical lens width of the secondemission lens 11 bB is 50% or less as great as the vertical lens widthof the first emission lens 11 b 1. By virtue of the second emissionlenses 11 bB having the vertical lens width that is 50% or less as greatas that of the first emission lenses 11 b 1, numerous small illuminationranges can be set in the entire illumination region. This improvesflexibility in setting the light distribution in the illuminationregion. The second emission lenses 11 bB of substantially the samevertical lens width are aligned as lens groups so as to have horizontalsymmetry with reference to the lens surface center CL of the emissionlens assemblage 11B. The second emission lenses 11 bB have the lensvertices TLb set to illuminate different regions in the secondillumination region E2 with the same vertical lens width and differentlight emitting directions.

As an example, the second emission lenses 11 bB have the lens verticesTLb set to oppose to the second incident lenses 11 aA and emit lightseparately in two ranges, and provided with the same vertical lens widthin order to receive light condensed by the second incident lenses 11 aA.In the present embodiment, the second emission lenses 11 bB includeemission 1st lenses 11 b 2 and emission 2nd lenses 11 b 3. The secondemission lenses 11 bB are aligned in the horizontal direction to formrows. The emission 1st lenses 11 b 2 and the emission 2nd lenses 11 b 3are each formed as a group of a preset number of lens rows across thevertical direction. The group of the emission 1st lenses 11 b 2 and thegroup of the emission 2nd lenses 11 b 3 form the second emission lensgroup 11ULB. That is, the second emission lens group 11ULB includes anemission 1st lens group 11UL2 and an emission 2nd lens group 11UL3.Accordingly, the second emission lens group 11ULB is formed of thegroups of the second emission lenses 11 bB the same as each other in thevertical lens width and emitting light of different illumination regionwidths.

Emission 1st Lenses

In the following, with reference to FIGS. 1 to 11, a description will begiven of the configuration of the emission 1st lenses 11 b 2 and theemission 2nd lenses 11 b 3.

As shown in FIGS. 1 to 7, the emission 1st lenses 11 b 2 are opticallyopposed to the incident 1st lenses 11 a 2 of the second incident lenses11 aA, and positioned and designed to have a size to receive light fromthe incident 1st lenses 11 a 2. The emission 1st lenses 11 b 2 have thelens vertices TLb eccentrically positioned so as to emit the receivedlight in the first range 1Eb of the second illumination region E2. Theemission 1st lenses 11 b 2 are smaller in the vertical lens width thanthe first emission lenses 11 b 1, and equivalent in the vertical lenswidth to the emission 2nd lenses 11 b 3. In the present embodiment, theemission 1st lenses 11 b 2 are the same in size and aligned in fourrows, to form an emission 1st lens row 11U21 to an emission 4th lens row11U24. The emission 1st lens row 11U21 to the emission 4th lens row11U24 form the emission 1st lens group 11UL2 in which all the emission1st lenses 11 b 2 in the four rows have the same size.

The emission 1st lenses 11 b 2 are aligned respectively continuously tothe upper and lower first emission lens groups 11UL1 of the firstemission lenses 11 b 1. That is, the emission 1st lenses 11 b 2 areformed as the emission 1st lens group 11UL2 including the emission 1stlens row 11U21 to the emission 4th lens row 11U24 continuously to thefirst emission lens groups 11UL1. The emission 1st lens group 11UL2 isformed at each of two locations, that is, one from the higher level tothe lower level in the emission lens assemblage 11B, and other from thelower level to the higher level in the emission lens assemblage 11B. Inthe present embodiment, the emission 1st lens groups 11UL2 are formed tobe continuous to the first emission lens groups 11UL1 so as to havehorizontal symmetry with reference to the lens surface center CL. Asused herein, the term horizontal symmetry refers to the disposition ofthe emission 1st lenses 11 b 2. Accordingly, while the shape of the lensvertices TLb may not have horizontal symmetry, the lens shape may alsohave horizontal symmetry. The usage of the term horizontal symmetryholds true for other lenses.

Emission 1st Lenses and Second Illumination Region

The emission 1st lenses 11 b 2 emit light in the first range 1Eb of thesecond illumination region E2. The emission 1st lenses 11 b 2 are formedto emit light from the lens rows divisionally in the first range 1Eb.The emission 1st lenses 11 b 2 have the lens vertices TLb eccentricallypositioned so that the whole first range 1Eb is illuminated by ranges oflight emitted from preset one or more lenses. Note that, the first range1Eb is formed by a maximum range where light beams from two adjacentemission 1st lenses 11 b 2 in each lens row are overlapped. The lightillumination intensity distribution of the maximum range is set by lightbeams emitted from all the emission 1st lenses 11 b 2 of the emissionlens group 11UL2. In the following, with reference to FIG. 8B, adescription will be given of the first range 1Eb.

As shown in FIG. 8B, the illumination range and the light illuminationintensity distribution of the whole first range 1Eb is set by the group(total) of individual ranges of light beams emitted from the emission1st lens row 11U21 to the emission 4th lens row 11U24 of the emission1st lenses 11 b 2. The individual illuminated ranges are set to havevertical symmetry with reference to the region center HCL in the widthdirection (the X-direction) of the first range 1Eb. The first range 1Ebincludes, as the individual illuminated ranges, a first section 1Eb1, asecond section 1Eb2, a third section 1Eb3, and a fourth section 1Eb4.That is, the four sections of the first range 1Eb are respectively setby the four lens rows. The emission 1st lens row 11U21 to the emission4th lens row 11U24 have the lens vertices TLb of the emission 1st lenses11 b 2 set so as to respectively emit light beams in the first section1Eb1 to the fourth section 1Eb4 of the first range 1Eb. Note that, thefirst section 1Eb1 to the fourth section 1Eb4 of the first range 1Eb areset to include the region center HCL, thereby overlapped on each otherby certain regions forming the center. As an example, each of the secondsection 1Eb2 to the fourth section 1Eb4 is formed as a group (total) oftwo subsections. In the following description, the odd numbered emission1st lens 11 b 2 is denoted by the reference character “11 b 2 d” with asuffix “d”, and the even numbered emission 1st lens 11 b 2 is denoted by“11 b 2 a” with a suffix “a”.

The emission 1st lens row 11U21 of the emission 1st lenses 11 b 2 hasthe lens vertices TLb of the emission 1st lenses 11 b 2 eccentricallyset so that, for example, the odd numbered and even numbered emission1st lenses 11 b 2 d, 11 b 2 a emit light in the first section 1Eb1. Thefirst section 1Eb1 is a quadrangle of which horizontal width andvertical width are set by the horizontal lens width and the verticallens width of the incident 1st lenses 11 a 2. In the present embodiment,the emission 1st lenses 11 b 2 mainly function to control the lightemitting direction.

Next, the emission 2nd lens row 11U22 of the emission 1st lenses 11 b 2has the lens vertices TLb eccentrically set so that, for example, theodd numbered emission 1st lens 11 b 2 d in the row emits light in onesubsection R1Eb2 of the second section 1Eb2. The emission 2nd lens row11U22 of the emission 1st lenses 11 b 2 has the lens vertices TLb set sothat the even numbered emission 1st lens 11 b 2 a in the row emits lightin other subsection L1Eb2 of the second section 1Eb2. That is, thesecond section 1Eb2 is formed by one subsection R1Eb2 and othersubsection L1Eb2. The one subsection R1Eb2 and other subsection L1Eb2have vertical symmetry with respect to the region center HCL. The secondsection 1Eb2 is greater than the first section 1Eb1 in the totalilluminated area in the horizontal direction (X-direction), and smallerthan the third section 1Eb3 and the fourth section 1Eb4 of the totalilluminated area in the horizontal direction.

Next, the emission 3rd lens row 11U23 of the emission 1st lenses 11 b 2have the lens vertices TLb eccentrically set so that the odd numberedemission 1st lens 11 b 2 d in the row emits light in one subsectionR1Eb3 of the third section 1Eb3, and the even numbered emission 1st lens11 b 2 a in the row emits light in other subsection L1Eb3 of the thirdsection 1Eb3. The one subsection R1Eb3 and the other subsection L1Eb3 ofthe third section 1Eb3 are set to have vertical symmetry and include theregion center HCL, thereby overlapped on each other by certain regionsforming the center. The one subsection R1Eb3 and the other subsectionL1Eb3 of the third section 1Eb3 form the overlapped central region atthe region center HCL that is smaller than the overlapped central regionformed by the one subsection R1Eb2 and the other subsection L1Eb2 of thesecond section 1Eb2. That is, the third section 1Eb3 extends fartherthan the second section 1Eb2 from the region center HCL in thehorizontal direction, and greater in the illuminated area.

Next, the emission 4th lens row 11U24 of the emission 1st lenses 11 b 2has the lens vertices TLb set so that the odd numbered emission 1st lens11 b 2 d in the row emits light in one subsection R1Eb4 of the fourthsection 1Eb4, and the even numbered emission 1st lens 11 b 2 a in therow emits light in other subsection L1Eb4 of the fourth section 1Eb4.The one subsection R1Eb4 and the other subsection L1Eb4 of the fourthsection 1Eb4 are set to have vertical symmetry and include the regioncenter HCL, thereby overlapped on each other by certain regions formingthe center. The one subsection R1Eb4 and the other subsection L1Eb4 ofthe fourth section 1Eb4 form the overlapped central region at the regioncenter HCL that is smaller than the overlapped central region formed bythe one subsection R1Eb3 and the other subsection L1Eb3 of the thirdsection 1Eb3. That is, the fourth section 1Eb4 is formed to be greaterthan the third section 1Eb3 in the illuminated area in the horizontaldirection. The fourth section 1Eb4 is set to be equivalent to the firstrange 1Eb.

The group (total illumination area) of the first section 1Eb1 to thefourth section 1Eb4 forms the first range 1Eb and sets the lightillumination intensity distribution. In the first range 1Eb, the lightillumination intensity distribution is set to be higher around theregion center HCL and lower toward the periphery. Note that, in thepresent embodiment, the first section 1Eb1, the one subsection of eachof the second section 1Eb2 to the fourth section 1Eb4, and the othersubsection of each of the second section 1Eb2 to the fourth section 1Eb4are the same as one another in size.

The ranges illuminated with light beams from the emission 1st lens row11U21 to the emission 4th lens row 11U24 of the emission 1st lenses 11 b2 gradually widen in the opposite sides from the region center HCL andincreased in the area as the lens rows are nearer to the lens surfacecenter CL.

As shown in FIGS. 10A and 10C, in the fly-eye lens 10, the emission 1stlens groups 11UL2 of the emission 1st lens 11 b 2 are formed at twolocations in the vertical direction. The light beams emitted from thetwo locations form the first range 1Eb. As shown in FIG. 8B, in theemission 1st lens group 11UL2 of the fly-eye lens 10, the centralportion of the first range 1Eb is overlapped on the central portion ofthe first illumination region E1, and right and left ends thereof extendoutward of the first illumination region E1.

Emission 2nd Lenses

As to the emission 2nd lenses 11 b 3 described in the following also,the second range 2Eb is formed of sections in the number correspondingto the lens rows, and each of the second and subsequent sections isformed of two subsections. As the lens rows are nearer to the lenssurface center CL, the two subsections increasingly extend toward theopposite sides with reference to the region center HCL. Therefore, whilethe reference characters are different, the foregoing description holdstrue for the emission 2nd lenses 11 b 3. Hence, in the description ofthe emission 2nd lenses 11 b 3, the above-described sections andsubsections forming the ranges will be referred to and details thereofwill not be repeated.

Next, as shown in FIGS. 1 to 7, the emission 2nd lenses 11 b 3 areoptically opposed to the incident 2nd lenses 11 a 3 of the secondincident lenses 11 aA. The emission 2nd lenses 11 b 3 are positioned andprovided with the size configured to receive light from the incident 2ndlenses 11 a 3. The emission 2nd lenses 11 b 3 have the lens vertices TLbeccentrically positioned so as to emit the received light in the secondrange 2Eb of the second illumination region E2. The emission 2nd lenses11 b 3 are equivalent in the vertical lens width to the emission 1stlenses 11 b 2. The emission 2nd lenses 11 b 3 are the same in size andaligned in six rows, to form an emission 1st lens row 11U31 to anemission 6th lens row 11U36.

The emission 1st lens row 11U31 to the emission 6th lens row 11U36 formthe emission 2nd lens group 11UL3 in which all the emission 2nd lenses11 b 3 of the six rows have the same size. The emission 2nd lenses 11 b3 are aligned respectively continuous to the upper and lower emission1st lens groups 11UL2 of the emission 1st lenses 11 b 2. That is, theemission 2nd lens 11 b 3 are formed as the emission 2nd lens group 11UL3including the emission 1st lens row 11U31 to the emission 6th lens row11U36 continuously to the emission 1st lens groups 11UL2. The emission2nd lens group 11UL3 is formed at each of two locations, that is, onefrom the higher level to the lower level in the emission lens assemblage11B, and other from the lower level to the higher level in the emissionlens assemblage 11B. In the present embodiment, the emission 2nd lensgroups 11UL3 are formed to be continuous to the emission 1st lens groups11UL2 so as to have horizontal symmetry with reference to the lenssurface center CL. Thus, two emission 2nd lens groups 11UL3, 11UL3 arecontinuously formed with reference to the lens surface center CL.

The emission 2nd lenses 11 b 3 emit light in the second range 2Eb of thesecond illumination region E2. The emission 2nd lenses 11 b 3 have thelens vertices TLb eccentrically positioned so that the emission 1st lensrow 11U31 to the emission 6th lens row 11U36 emit light beams in thesections and subsections within the second range 2Eb. That is, theemission 2nd lenses 11 b 3 have the lens vertices TLb eccentricallypositioned so that the second range 2Eb is set by the group (total) ofranges of light beams emitted from the preset lens rows.

Illumination Region by Emission 2nd Lenses, First Section to FourthSection of Second Range

As shown in FIG. 8C, the second range 2Eb is set by a group of: sectionsformed by the emission 1st lens row 11U31 that is the first row in thelens group; and sections and subsections each obtained by dividing onesection formed by the emission 2nd lens row 11U32 to the emission 6thlens row 11U36 that is the last lens row. The second range 2Eb has itssection or subsection disposed to have vertical symmetry with referenceto the region center HCL. The emission 1st lens row 11U31 to theemission 6th lens row 11U36 are designed so that, as the rows are nearerto the lens surface center CL, the sections forming the second range 2Ebare positioned increasingly outward with reference to the region centerHCL. The emission 2nd lenses 11 b 3 emit light in the second range 2Ebthat is smaller than the first range 1Eb in the vertical direction andextends outward of the first range 1Eb with reference to the regioncenter HCL. While the second range 2Eb corresponding to the emission 2ndlenses 11 b 3 is different from the already described first range 1Ebcorresponding to the emission 1st lenses 11 b 2 in the positionalrelationship and size, the difference from the first section 1Eb1 to thefourth section 1Eb4 of the first range 1Eb just lies in the number ofthe sections and reference characters, and the second range 2Eb issimilarly formed of regions including sections and subsections.Therefore, the description thereof will not be repeated.

Further, as shown in FIGS. 6 and 7 (see FIG. 10A), in the fly-eye lens10, the emission 2nd lens group 11UL3 is formed at each of two locationsso as to have horizontal symmetry with reference to the lens surfacecenter CL. Thus, the second range 2Eb is formed by light beams emittedfrom the two locations. As shown in FIGS. 9C and 9D, in the fly-eye lens10, the second range 2Eb are formed to spread outward of the first range1Eb with reference to the region center HCL. In the present embodiment,as compared to the emission 1st lens group 11UL2 emitting light in thefirst range 1Eb, the emission 2nd lens group 11UL3 is nearer to the lenssurface center CL. Therefore, the second range 2Eb is overlapped at itscenter on the first illumination region E1 and becomes wider toward theopposite ends in the horizontal direction from the region center HCL.

Illumination Region

As has been described, as shown in FIGS. 9A and 10A, when light becomesincident on the incident lens assemblage 11A as collimated light beams,the fly-eye lens 10 formed of the incident lenses 11 a and the emissionlenses 11 b emits the light beams from the emission lens assemblage 11Bin the first illumination region E1 and the second illumination regionE2. The fly-eye lens 10 emits light so as to attain a preset lightillumination intensity distribution in the first illumination region E1of the illumination region EA, and a preset light illumination intensitydistribution in the second illumination region E2 of the illuminationregion EA. The fly-eye lens 10 emits light so that central partialportion of the first range 1Eb and the second range 2Eb of the secondillumination region E2 is overlapped on the first illumination region E1while having vertical symmetry relative to the first illumination regionE1. Accordingly, in the illumination region EA, a desired gray scaledistribution is attained, that is, the light illumination intensitydistribution in the whole illumination region is higher at the centerand lower toward the periphery of the illumination region EA. In theillumination region EA, setting the first illumination region E1 and thesecond illumination region E2 sets all the ranges in the illuminatedregion. That is, by setting the illuminated region in the illuminationregion EA to be 70% as great as the illumination region EA, the definedlight illumination intensity distribution of the entire region issecured. It goes without saying that the illumination region EA may beset by light emission in the whole region by the first illuminationregion E1 and the second illumination region E2, or the firstillumination region E1 or the second illumination region E2.

As shown in FIGS. 10A to 10D, the first illumination region E1 and thesecond illumination region E2 are formed by a group of illuminationranges illuminated with light beams BL1 to BL6 of the first emissionlens group 11UL1 or lens groups of the second emission lenses 11 bB. Thefirst illumination region E1 is set at the central region in therectangular illumination region EA, and illuminated with light from thefirst emission lens group 11UL1 disposed at each of two upper and lowerlocations in the fly-eye lens 10. Similarly, the second illuminationregion E2 is formed by a group of illumination ranges illuminated withlight beams from the lens groups. The second illumination region E2 isilluminated with light from the lens groups respectively disposed at twoupper and lower locations in the fly-eye lens 10, so as to be partiallyoverlapped on the central region in the rectangular illumination regionEA. For example, as shown in FIGS. 8B and 8C, the first range 1Eb andthe second range 2Eb are divided into the first section 1Eb1 to thefourth section 1Eb4, or the first section 2Eb to the sixth section 2Eb6.Each of the sections are further divided into one subsection and othersubsection. Therefore, with light emitted from the emission 1st lensgroup 11UL2 of the second emission lenses 11 bB, a light illuminationintensity distribution of the whole illumination region can be set to behigher around the region center HCL and lower toward the periphery.Similarly to the first illumination region 1E, the second range 2Eb ofthe second illumination region E2 can be set to have a lightillumination intensity distribution of the whole illumination regionthat is higher around the region center HCL and lower toward theperiphery.

Accordingly, in the fly-eye lens 10, with the first illumination regionE1 and the second illumination region E2, the light illuminationintensity distribution of the whole illumination region is easily set tobe higher around the region center HCL and lower toward the periphery.By the vertical range of first range 1Eb and the second range 2Eb of thesecond illumination region E2 being set 50% or less as great as thevertical range of the first illumination region E1, the lightillumination intensity distribution in the illumination region EA iseasily adjusted and setting flexibility improves.

In the fly-eye lens 10, the lens groups and the lens rows are arrangedto have vertical symmetry with reference to the lens surface center CL.The emission 1st lenses 11 b 2 and the emission 2nd lenses 11 b 3 of thefirst emission lenses 11 b 1 to the second emission lenses 11 bB areequivalent in the horizontal lens width and the vertical lens width withreference to the lens surface center CL. This makes it easier to alignand connect the lenses in forming the fly-eye lens 10.

In the fly-eye lens 10, at least one lens group of the second incidentlens groups 11NLA aligned in the vertical direction is different in thenumber of lens rows from other lens groups. At least one lens group ofthe second emission lens groups 11ULB aligned in the vertical directionis different in the number of lens rows from other lens groups. In thefly-eye lens 10, the second incident lens group 11NLA and the secondemission lens group 11ULB in different number of lens rows are opticallyopposed to each other, with the difference in the lens rows being thesame between them.

That is, in the fly-eye lens 10, the number of lens rows in the incident1st lens group 11NL2 and the incident 2nd lens group 11NL3 of the secondincident lens group 11NLA is four or six, which is the difference in thenumber of lens rows in one lens group. In the fly-eye lens 10, thenumber of lens rows in the emission 1st lens group 11UL2 and theemission 2nd lens group 11UL3 of the second emission lens group 11ULB isfour or six, which is the difference in the number of lens rows in onegroup. In the fly-eye lens 10, the difference in the number of lens rowsbetween the lens groups is the same between the incident side and theemission side.

In this manner, the lens rows in the lens groups are set as desired inthe fly-eye lens 10 and, therefore, the illumination region EA is set asdesired.

First range of illumination region: first section to fourth section offirst range

The ranges illuminated with light from the lens rows of the fly-eye lens10 may be set as shown in FIGS. 11, 12A to 12C, for example.

With reference to FIG. 11, a description will be given of the emission1st lenses 11 b 2 of the second emission lenses 11 bB representing thelens rows of the emission 1st lenses 11 b 2 and the emission 2nd lenses11 b 3 of the first emission lenses 11 b 1 and the second emissionlenses 11 bB.

As shown in FIG. 11, the emission 1st lens row 11U21 of the emission 1stlens group 11UL2 has the lens vertices TLb positioned so that onesubsection R1Eb1 in the first section 1Eb1 forming the first range 1Ebis illuminated with light from the odd numbered emission 1st lens 11 b 2d. The emission 1st lens row 11U21 has the lens vertices TLb positionedso that other subsection L1Eb1 in the first section 1Eb1 forming thefirst range 1Eb is illuminated with light from the even numberedemission 1st lenses 11 b 2 a. The first section 1Eb1 is set to the rightend range in the first range 1Eb. The first section 1Eb1 is partiallyoverlapped on the region center HCL, and formed by the one subsectionR1Eb1 and the other subsection L1Eb1.

The emission 2nd lens row 11U22 of the emission 1st lens group 11UL2 hasthe lens vertices TLb positioned so that one subsection R1Eb2 in thesecond section 1Eb2 forming the first range 1Eb is illuminated withlight from the emission 1st lens 11 b 2 a of the odd numbered emission1st lens 11 b 2 d. The emission 2nd lens row 11U22 has lens vertices TLbpositioned so that other subsection L1Eb2 in the second section 1Eb2forming the first range 1Eb is illuminated with light from the evennumbered emission 1st lens 11 b 2 a. The second section 1Eb2 is formedby the one subsection R1Eb2 and the other subsection L1Eb2. The secondsection 1Eb2 is disposed toward the region center HCL than the firstsection 1Eb1 is and rightward than the third section 1Eb3, to bepartially overlapped on the region center.

The emission 3rd lens row 11U23 of the emission 1st lens group 11UL2 hasthe lens vertices TLb positioned so that one subsection R1Eb3 in thethird section 1Eb3 forming the first range 1Eb is illuminated with lightfrom the odd numbered emission 1st lens 11 b 2 d. The emission 3rd lensrow 11U23 has the lens vertices TLb positioned so that other subsectionL1Eb3 in the third section 1Eb3 forming the first range 1Eb isilluminated with light from the even numbered emission 1st lens 11 b 2a. The third section 1Eb3 is formed by the one subsection R1Eb3 and theother subsection L1Eb3. The third section 1Eb3 and the second section1Eb2 have vertical symmetry with respect to and the region center HCL.The third section 1Eb3 is partially overlapped on the region center HCL.

The emission 4th lens row 11U24 of the emission 1st lens group 11UL2 hasthe lens vertices TLb positioned so that one subsection R1Eb4 in thefourth section 1Eb4 forming the first range 1Eb is illuminated withlight from the odd numbered emission 1st lens 11 b 2 d. The emission 4thlens row 11U24 has the lens vertices TLb positioned so that othersubsection L1Eb4 in the fourth section 1Eb4 forming the first range 1Ebis illuminated with light from the even numbered emission 1st lens 11 b2 a. The fourth section 1Eb4 is formed by the one subsection R1Eb4 andthe other subsection L1Eb4. The fourth section 1Eb4 and the firstsection 1Eb1 have vertical symmetry with respect to the region centerHCL. The fourth section 1Eb4 is partially overlapped on the regioncenter HCL.

In this manner, the first range 1Eb may be formed by a plurality ofsections of substantially the same area across its one end to its otherend. Each of the sections of the first range 1Eb is formed of twosubsections, namely, the one subsection and the other subsection.

In the case in which the number of lens rows forming the lens group isan odd number, the sections should be disposed so that any one of thelens rows has symmetry with respect to the region center HCL, theillumination range of which one lens row is set by a plurality ofsections. Thus, the light illumination intensity distribution of thewhole illumination range attains vertical symmetry with respect to theregion center HCL.

Setting the lens vertices TLb of the lens rows in FIG. 11, the positionof the even numbered and odd numbered lens vertices TLb gradually changefrom one end side toward other end side of the lens rows. The settingmay be selectively determined in accordance with the purpose.

The first illumination region E1 may also be set in the manner shown inFIG. 11. The second range 2Eb, which is the other region range in thesecond illumination region E2, may similarly be set to have a lightillumination intensity distribution which is higher at the center andlower toward the opposite sides in the horizontal direction.

Other Illumination Region With Other Lens Row Configuration

Next, the lens row configuration and illumination regions as shown inFIGS. 12A to 12C may be employed. In this configuration, one lens row isset to have an illumination range positioned rightward or leftward withreference to the region center HCL.

With reference to FIGS. 12A to 12C, a description will be given ofemission 1st lenses 11 b 2 of the second emission lenses 11 bBrepresenting the lens rows of the emission 1st lenses to the emission5th lenses of the first emission lenses 11 b 1 and the second emissionlenses 11 bB. As an example, each lens row includes four lenses intotal. The odd numbered emission 1st lens 11 b 2 is demoted by thereference character “11 b 2 d” with a suffix “d”, and the even numberedemission 1st lens 11 b 2 is denoted by “11 b 2 a” with a suffix “a”.

As shown in FIG. 12A, the emission 1st lens row 11U21 of the emission1st lens group 11UL2 is set to emit light in a plurality of sectionsforming the first range 1Eb. In this configuration, the first range 1Ebis set by one section R1Eb and other section L1Eb which have verticalsymmetry and are partially overlapped on the region center HCL. Theemission 1st lens row 11U21 have the lens vertices TLb positioned sothat the one subsection R1Eb is illuminated with light from the oddnumbered emission 1st lens 11 b 2 d as shown in FIG. 12B, and the othersubsection L1Eb is illuminated with light from the even numberedemission 1st lens 11 b 2 a shown in FIG. 12C. Similarly to the emission1st lens row 11U21, other lens rows of the emission 1st lens group 11UL2have the lens vertices TLb positioned so that the one subsection R1Eb isilluminated with light from the odd numbered emission 1st lens 11 b 2 dand the other subsection L1Eb is illuminated with light from the evennumbered emission 1st lens 11 b 2 a.

In this manner, in the fly-eye lens, in each lens row in each lensgroup, the even numbered and odd numbered lens vertices TLb arealternately assigned to the one subsection and the other subsection, toset the illumination region. Thus, each lens group is formed of lenseswith smaller variations in the position of the lens vertices TLb.Therefore, in forming the fly-eye lens, variations in the lens surfacebecomes small.

The first illumination region E1 can also be set as shown in FIGS. 12Ato 12C. The second range 2Eb which is the other region range in thesecond illumination region E2 may similarly be set to have a lightillumination intensity distribution that is higher at the center andlower toward the opposite sides in the horizontal direction.

Configuration of Illumination Region as Variation

The fly-eye lens 10 has been described to include the incident lenseswith three types of vertical lens width and the emission lenses with twotypes of vertical lens width, to set the illumination region EA. Here,as shown in FIGS. 13A and 13B, the second illumination region E2 may beformed by a greater number of ranges. For example, the fly-eye lens maybe formed with the second incident lenses 11 aA and the second incidentlenses 11 bB with five types of vertical lens width, so that the secondillumination region E2 is formed by the first range 1Eb to the fifthrange 5Eb. The illumination state of the illumination region EA withincreased ranges can be more minutely set. Note that, FIG. 13B shows, bythe gray scale, the light illumination intensity distribution of theillumination region EA including the first illumination region E1 andthe second illumination region E2 including the first range 1Eb to fifthrange 5Eb (a whiter tone represents higher light illuminationintensity). In the fly-eye lens 10, when the vertical lens width of theincident lenses is varied, the vertical lens width of the emissionlenses receiving light to be condensed may not be varied. In the fly-eyelens 10, the range of the illumination region is controlled by the shapeof the incident lenses, and the light emission direction is controlledby the position of the lens vertices TLb of the emission lenses. Hence,the emission lenses may have a single vertical lens width.

Variation of Fly-Eye Lens

As shown in FIG. 14A, a fly-eye lens 10A may be obtained by invertingthe concave and convex of the incident lens assemblage 11A and theemission lens assemblage 11B of the fly-eye lens 10 shown in FIG. 1.That is, in the fly-eye lens 10A, the incident lens assemblage 11A1 isconvex around the lens surface center CL, and concave at the upper andlower positions with respect to the lens surface center. In the fly-eyelens 10A, the emission lens assemblage 11B1 is concave around the lenssurface center CL, and concave at the upper and lower positions withrespect to the lens surface center CL. In the fly-eye lens 10A, thefirst incident lenses 11 a 1 and the first emission lenses 11 b 1 with agreater vertical lens width are disposed around the lens surface centerCL. On the upper and lower sides with respect to the first incidentlenses 11 a 1, the second incident lenses 11 aA of which vertical lenswidth becomes gradually smaller toward the upper and lower edges aredisposed so as to have horizontal symmetry. On the upper and lower sideswith reference to the first emission lens 11 b 1, the second emissionlenses 11 bB of which vertical lens width becomes smaller toward theupper and lower edges are disposed so as to have horizontal symmetry.The fly-eye lens 10A in this configuration similarly properly sets thefirst illumination region and the second illumination region in theillumination region. In the fly-eye lens 10A, the second emission lenses11 bB may all be the same in the vertical lens width.

Furthermore, the fly-eye lens may have a plurality of cylindrical lensaligned in the column direction, each being one in number in the rowdirection, to form the incident lenses and the emission lenses. Onefly-eye lens may employ a single or a plurality of groups of lenses ofwhich vertical lens width is varied in the column direction. In the casein which cylindrical lenses are employed, the whole illumination regionis illuminated having the illumination ranges illuminated by the lensgroups varied in the vertical direction with an equivalent illuminationwidth in the horizontal direction. The present disclosure is not limitedto the configuration in which one lens is aligned in the verticaldirection as the fly-eye lens. It goes without saying that two or threecylindrical lenses may be arranged in the horizontal direction to belens rows, which lens rows may be repetitively arranged in the verticaldirection.

Variation of Illumination Region

Without being limited to the light illumination intensity distributionof the illumination region EA shown in FIG. 13B, the fly-eye lens 10,10A may be configured as shown in FIGS. 14B and 14C, for example. InFIG. 14B, the light illumination intensity distribution of the wholeillumination region EA2 is higher at the central portion and lowertoward the right and left edges. Such an illumination region EA2 can beattained by having the shape of the incident lenses 11 a set and thelens vertices TLb of the emission lenses 11 b of the fly-eye lenseccentrically positioned. For example, similarly to the second emissionlens 11 bB, the first emission lenses 11 b 1 may have the lens verticesTLb eccentrically positioned so that the odd numbered and even numberedlenses are respectively allotted to the left and right sides of theillumination region EA to spread the range illuminated by the lightemitted from the lenses in the horizontal direction (the X-direction).Alternatively, the light illumination intensity distribution as in theillumination region EA2 may be attained by having the lens vertices TLbeccentrically positioned so that the light beams from the lens groups ofthe second emission lens 11 bB fall within the range of the firstillumination region E1 in the horizontal direction.

Similarly, as shown in FIG. 14C, the light illumination intensitydistribution in the illumination region EA3 is higher about its centerand lower toward its four sides. Such an illumination region EA3 can beattained by having the lens vertices TLb of the first emission lenses 11b 1 and the second emission lenses 11 bB of the fly-eye lenseccentrically positioned.

The eccentrically positioning the lens vertices TLb may be performed, asdescribed above, for each lens group or lens rows, to form the fly-eyelens. Because light beams from the incident lenses 11 a are condensed inthe fly-eye lens 10, 10A, the emission lenses 11 b may be equivalent toeach other in the vertical lens width.

The first illumination region E1 may be formed by, in the wholeillumination region EA, a group of regions illuminated at differentlocations with light emitted from rows of the first emission lenses 11 b1, which regions are the same as one another in the vertical region sizeand differ from one another in the horizontal region size.

The second illumination region E2 may be formed by, in the wholeillumination region EA, a group of regions illuminated at differentlocations with light emitted from rows of the second emission lenses 11bB, which regions differ from one another in the vertical region sizeand the same as one another in the horizontal region size.

The first illumination region E1 may be formed by, in the wholeillumination region, a group of regions illuminated at differentlocations with light emitted from rows of the first emission lenses 11 b1, which regions are the same as one another in the vertical region sizeand the horizontal region size.

The second illumination region E2 may be formed by, in the wholeillumination region EA, a group of regions illuminated at differentlocations with light emitted from rows of the second emission lenses 11bB, which regions are the same as one another in the vertical regionsize and the horizontal region size.

Illumination Optical Device

Next, with reference to FIG. 15, a description will be given of anillumination optical device 100. In this configuration, the fly-eye lens10 is exemplarily used.

The illumination optical device 100 is used as any of various lightingdevices for a vehicle, a ship, or an aircraft, for example. Theillumination optical device 100 includes: a light source 20; a firstoptical member 30 configured to convert light from the light source 20to a collimated light beam; the fly-eye lens 10 configured to receivethe light from the first optical member 30 and emit the light with adesired light illumination intensity distribution; a second opticalmember 55 configured to adjust the light from the fly-eye lens 10; alight modulation device 60 configured to receive the light from thesecond optical member 55 and emit the light in a different optical path;and a projection lens 70 configured to project the light from the lightmodulation device 60. These elements from the light source 20 to theprojection lens 70 are housed in a frame.

The light source 20 is configured to emit, for example, white-colorlight. The light source 20 may be, for example, a light emitting devicethat includes a light emitting element housed in a package, and alight-transmissive member. The light emitting element may be any knownlight emitting element. For example, the light emitting element maypreferably be a light emitting diode or a laser diode. The lightemitting element may have any wavelength. For example, a light emittingelement emitting blue-color or green-color light may be formed using anitride-based semiconductor (In_(X)Al_(Y)Ga_(1-X-Y)N, 0≤X, 0≤Y, X+Y≤1),or a GaP. A light emitting element emitting red-color light may beformed using GaAlAs, AlInGaP or the like. The light emitting element maybe a semiconductor light emitting element formed using any materialother than the foregoing materials. The composition, the color ofemitted light, and the number of the light emitting element may beselected as appropriate in accordance with the intended use.

The package is formed of, for example, conductive members such as a leadframe or wires with which the light emitting element is mounted,ceramic, and a resin molded body. The resin molded body of the packageis a reflective member formed of epoxy resin or silicone resin. Theceramic of the package is alumina or aluminum nitride. Electricalconnection between the light emitting element and the outside isestablished via the conductive member. The light-transmissive member isprovided to cover the light emitting element mounted on the inner leadportion of the lead frame. The light-transmissive member may beconfigured to include a wavelength conversion member such as afluorescent material or a diffusing member.

As an example, the first optical member 30 is a collimating lens. In thepresent embodiment, the first collimating lens 31 and the secondcollimating lens 32 converts light from the light source 20 into acollimated light beam. The collimating lens in this configuration may bea compound lens such as a combination of a concave lens and a convexlens, a combination of convex lenses, or a simple lens, so long as thecollimating lens is capable of converting light from the light source 20to a collimated light beam.

The fly-eye lens 10 is configured as described above. The fly-eye lens10 is set to emit light in the illuminated surface of the lightmodulation device 60 in a desired light illumination intensitydistribution. So long as a desired light illumination intensitydistribution is attained, the number of lens groups or lens rows of thefly-eye lens 10 is not specified. The shape of the lens surface of theincident lens assemblage of the fly-eye lens 10 or the shape of the lenssurface of the emission lens assemblage is not specified.

The second optical member 55 is disposed on the optical path between thefly-eye lens 10 and the light modulation device 60 so as to cause lightfrom the fly-eye lens 10 to become incident on the illuminated surfaceof the light modulation device 60. In the present embodiment, the secondoptical member 55 is a condenser lens 40 and a field lens 50. Thecondenser lens 40 is configured to cause light from the fly-eye lens 10to be superimposed on the light modulation device 60. The condenser lens40 condenses light emitted from the fly-eye lens 10 to fall within arange corresponding to the illuminated surface of the light modulationdevice 60 via the field lens 50. The field lens 50 adjusts the angle oflight becoming incident on the light modulation device 60.

The light modulation device 60 is configured to change the optical pathof light emitted from the fly-eye lens 10 with a desired lightillumination intensity distribution via the second optical member 55,and output the light of which distribution is variable. The lightmodulation device 60 is, for example, a DMD (digital micromirrordevice). The light modulation device 60 controls a plurality ofmicromirrors to selectively produce light. Because the supplied lightalready has a desired light illumination intensity distribution, thelight modulation device 60 can reflect the light with a 100% gray scaledistribution by the micromirrors without any loss in luminous flux, tosend the light to the projection lens 70. That is, the light modulationdevice 60 is capable of realizing, for example as a luminous intensitydistribution required of a headlamp, the characteristic in which theintensity is higher about the center and lower toward the periphery ofthe whole illumination region without any loss in luminous flux.

The projection lens 70 is configured to spread the light sent from thelight modulation device 60 and projects the light on the image-formingplane. The projection lens 70 may be a simple lens or a compound lens.The projection lens 70 sends the light received from the lightmodulation device 60 to the image-forming plane at a preset distance ina desired light illumination intensity distribution.

The illumination optical device 100 configured as described aboveadjusts the light from the light source 20 to have a desired lightillumination intensity distribution through the fly-eye lens 10, andoutputs the light through the light modulation device 60 without anyloss in luminous flux, and to emit the light to the outside through theprojection lens 70. The fly-eye lens 10, 10A is easily formed without agreat height step.

Variation of Illumination Optical Device

The illumination optical device 100 may have, as the first opticalmember 30, the configuration shown in FIGS. 16A and 16B.

As shown in FIG. 16A, a paraboloid reflecting mirror 33 may be providedas a first optical member 30A. The paraboloid reflecting mirror 33 isdisposed to reflect light emitted from the light source 20, so that thelight becomes incident on the fly-eye lens 10 as a collimated lightbeam. In using the paraboloid reflecting mirror 33, the light source 20is disposed to emit light toward the paraboloid reflecting mirror 33.The light source 20 is disposed at the focus position of the paraboloidreflecting mirror 33.

As shown in FIG. 16B, an oval reflecting mirror 34 may be provided as afirst optical member 30B. Using the upper half of the oval curvedsurface, the oval reflecting mirror 34 reflects light from the lightsource 20 as a collimated light beam. The light source 20 is disposed byan angle and at a position so that the light emitted toward the ovalreflecting mirror 34 becomes a collimated light beam.

Variation of Configurations

As described above, the configurations of the fly-eye lens 10, 10A andthe illumination optical device 100 are not specified to those describedabove.

For example, the first illumination region E1 may be formed of a regiondivided into a plurality of sections. While the second illuminationregion E2 has been described, as an example, to be formed by two ranges,the second illumination region E2 may be formed of one, three, or fourranges, or six to twelve or more ranges. While the second illuminationregion E2 has been described to be formed by a plurality of rangesdiffering from one another in the illuminated area, the ranges may bethe same in the area and different from one another while varied in theilluminated positioned to form the second illumination region E2. Thelens groups of the fly-eye lens should just be the same in thehorizontal lens width, and the vertical lens width may not be in agradually increasing or reducing order. That is, in the fly-eye lens,for example, the even numbered lens group may be disposed after the oddnumbered lens group so as to have horizontal symmetry with reference tothe lens surface center CL. The fly-eye lens has been described toinclude the incident lenses 11 a of the first incident lenses and thesecond incident lenses, and the emission lenses 11 b of the firstemission lenses and the second emission lenses, which are differing fromeach other just in the vertical lens width and the same in the function.That is, the numbering of the first and the second is just for theconvenience of description style. While the lenses and the lens rows ofthe fly-eye lens have been described from the first in order on theincident side and the emission side, the numbering is just for theconvenience of description style. While the fly-eye lens 10, 10A hasbeen described that two lens groups having vertical symmetry withrespect to the lens surface CL illuminate the same region or range, onelens group may illuminate one region or range.

As to the illumination region EA, the distinction has been drawn betweenthe first illumination region E1 and the second illumination region E2for their being different in the vertical illumination width and in theillumination position. Here, the illumination region EA may be formed ofa plurality of regions, sections each forming the region, or subsectionseach forming the section. In the case in which the illumination regionEA is formed of a plurality of regions, sections each forming theregion, or subsections each forming the section, as shown in FIGS. 8A to8C, 11, and 12A to 12C, the lens vertices should be eccentricallypositioned for each lens, for each lens row, or for each lens group.Note that, the illumination region EA is formed of a group of regions(including ranges, sections and subsections) in which light isilluminated from the emission lenses of the fly-eye lens.

In the fly-eye lens 10, 10A, in addition to the lens width being set tobe the same in one of the column direction and the row direction, thenumber of lens groups or the number of lens rows forming each lens groupmay be set to be the same, partially different, or entirely different.That is, adjusting the lens rows of the lens group improves flexibilityin setting the illumination region EA. The fly-eye lens 10, 10A maydispense with the lens upper frame part 12, the lens lower frame part13, the lens left frame part 14, and the lens right frame part 15, andmay have simple lenses bonded to one another (see FIG. 1). While thefly-eye lens 10, 10A has been described to have emission lenses that areequivalent to one another in the vertical lens width, the emissionlenses may have the vertical lens width varied similarly to the opposedlenses of the incident lenses. In the fly-eye lens, the number of theincident lenses and the emission lenses aligned in the row direction maybe even or odd. When the number of the lens is an even number, thelenses are formed so that the lens vertex of the central lens in thelens row is not eccentrically positioned (the lens vertex agrees withthe optical axis of the lens).

As to the second emission lenses 11 bB, it has been described that thehorizontal lens width is set to attain the illuminated area half or lessas great as the maximum region in the second illumination region. Here,the maximum region of the illumination region in the second illuminationregion may be greater than the total area of the horizontal lens widthof two lenses. That is, in the fly-eye lens, the illumination regionshould be formed by the total regions of the plurality of lenses, toattain a desired light illumination intensity distribution. Furthermore,when the horizontal lens width is the same in the vertical columndirection (the Z-direction), the horizontal lens width may not be thesame in the adjacent vertical column direction. The horizontal lenswidth being the same in the vertical direction provides the fly-eye lenswith a smaller step height. In the case in which the horizontal lenswidth is different for each vertical column, the illuminated regions arevaried in the area. This improves the flexibility in setting the lightillumination intensity distribution in the illumination region.

The fly-eye lens may be formed by having the lenses connected so thatthe shape of the lens surface of the incident lenses and the emissionlenses becomes a flat plane in the vertical direction. The fly-eye lensmay have at least one of a convex surface and a concave surface formedat the lens surface on the incident lens side, and the emission lens maybe formed to be substantially parallel to the lens surface on theincident lens side.

As to the illumination optical device 100, while the light modulationdevice 60 has been exemplarily described as a DMD, the light modulationdevice 60 may be other device, such as a spatial light modulator.

INDUSTRIAL APPLICABILITY

The fly-eye lens and the illumination optical device of the presentdisclosure is applicable to an optical system or an illumination deviceof a light source for any of various lighting devices of a vehicle suchas a motorcycle or an automobile, or a conveyance such as a ship or anaircraft. The fly-eye lens and the illumination optical device of thepresent disclosure are applicable also to an optical system or anillumination device of any of various illumination light sources such asspotlight, a light source for a display, an onboard component, aninterior lighting, an outdoor lighting and the like.

DENOTATION OF REFERENCE NUMERALS

-   10, 10A: fly-eye lens-   11A: incident lens assemblage-   11B: emission lens assemblage-   11 a: incident lens-   11 b: emission lens-   11 a 1: first incident lens-   11 b 1: first emission lens-   11 aA: second incident lens-   11 bB: second emission lens-   11 a 2: incident 1st lens-   11 b 2: emission 1st lens-   11 a 3: incident 2nd lens-   11 b 3: emission 2nd lens-   11NL1: first incident lens group-   11U11: first emission lens group-   11N11: incident 1st lens row-   11U11: emission 1st lens row-   11N12: incident 2nd lens row-   11U12: emission 2nd lens row-   11N13: incident 3rd lens row-   11U13: emission 3rd lens row-   11NLA: second incident lens group-   11ULB: second emission lens group-   11NL2: incident 1st lens group-   11UL2: emission 1st lens group-   11N21: incident 1st lens row-   11U21: emission 1st lens row-   11N22: incident 2nd lens row-   11U22: emission 2nd lens row-   11N23: incident 3rd lens row-   11U23: emission 3rd lens row-   11N24: incident 4th lens row-   11U24: emission 4th lens row-   11NL3: incident 2nd lens group-   11UL3: emission 2nd lens group-   11N31: incident 1st lens row-   11U31: emission 1st lens row-   11N32: incident 2nd lens row-   11U32: emission 2nd lens row-   11N33: incident 3rd lens row-   11U33: emission 3rd lens row-   11N34: incident 4th lens row-   11U34: emission 4th lens row-   11N35: incident 5th lens row-   11U35: emission 5th lens row-   11N36: incident 6th lens row-   11U36: emission 6th lens row-   11RA1: incident-side concave surface-   11RB1: emission-side convex surface-   11RA2: incident-side convex surface-   11RB2: emission-side concave surface-   12: lens upper frame part-   13: lens lower frame part-   14: lens left frame part-   15: lens right frame part-   20: light source-   30: first optical member-   31: first collimating lens-   32: second collimating lens-   40: condenser lens-   50: field lens-   55: second optical member-   60: light modulation device-   70: projection lens-   CL: lens surface center-   E1: first illumination region-   E2: second: illumination region-   EA, EA1, EA2: illumination region-   HCL: region center-   TLb: lens vertex of emission lens-   TLa: lens vertex of incident lens-   L1Eb: other section-   R1Eb: one section-   L1Eb1, L1Eb2, L1Eb3, L1Eb4: other subsection-   R1Eb1, R1Eb2, R1Eb3, R1Eb4: one subsection

What is claimed is:
 1. A fly-eye lens comprising: an incident lensassemblage comprising a plurality of incident lenses that are aligned ina vertical direction, wherein each of the incident lenses has aquadrangular shape, wherein horizontal lens widths of the incident lensare the same, and wherein vertical lens widths of at least some of theincident lens are different from one another; and an emission lensassemblage comprising a plurality of emission lenses that are aligned inthe vertical direction so as to be optically opposed to the incidentlenses, wherein each of the emission lenses has a quadrangular shape,and wherein horizontal lens widths of the emission lenses lens are thesame; wherein a dimension of the quadrangular shape of the incidentlenses is set such that, on an illuminated surface, a presetillumination region is attained by a group of illumination ranges, eachilluminated with light from one or more of the incident lenses, andwherein lens vertices of the incident lenses are eccentricallypositioned such that light supplied by the incident lenses to theemission lenses is optically opposed to the incident lenses; and whereina dimension of the quadrangular shape of the emission lenses is set andlens vertices of the emission lenses are positioned such that any of theplurality of illumination ranges forming the preset illumination regionis attained, and such that at least part of the illumination ranges areoverlapped with each other.
 2. The fly-eye lens according to claim 1,wherein: the incident lens assemblage comprises one or more incidentlens rows that are adjacent in the vertical direction, each of the oneor more incident lens rows comprising a plurality of the incident lensesthat are aligned in the horizontal direction; the emission lensassemblage comprises one or more emission lens rows that are adjacent inthe vertical direction, each of the one or more emission lens rowscomprising a plurality of the emission lenses that are aligned in thehorizontal direction; and any of the illumination ranges is illuminatedwith light from each of the rows of the emission lenses.
 3. The fly-eyelens according to claim 1, wherein: the incident lenses comprise: one ormore first incident lens rows that are adjacent in the verticaldirection, each of the one or more first incident lens rows comprising aplurality of first incident lenses that are aligned in the horizontaldirection, and one or more second incident lens rows that are adjacentin the vertical direction, each of the one or more second incident lensrows comprising a plurality of second incident lenses that are alignedin the horizontal direction, wherein the one or more second incidentlens rows are continuous with the one or more first incident lens rows,and wherein a vertical lens width of the second incident lenses issmaller in a vertical lens width of the first incident lenses; theemission lenses comprise: one or more first emission lens rows that areadjacent in the vertical direction, each of the one or more firstemission lens rows comprising a plurality of first emission lenses thatare aligned in the horizontal direction, and one or more second emissionlens rows that are adjacent in the vertical direction, each of the oneor more second emission lens rows comprising a plurality of secondemission lenses that are aligned in the horizontal direction, whereinthe one or more second emission lens rows are continuous with the one ormore first emission lens rows; the illumination region includes a firstillumination region illuminated with light emitted from the firstemission lenses and a second illumination region illuminated with lightemitted from the second emission lenses; and the lens vertices of theemission lenses are positioned so as to emit light, by each lens row, inthe first illumination region or the second illumination region of theillumination range.
 4. The fly-eye lens according to claim 3, wherein:the first incident lenses and the second incident lenses each form alens group by a preset number of the incident lens rows, the lens grouphas the quadrangular shape formed to illuminate any of the illuminationranges; the first emission lenses and the second emission lenses eachform a lens group by a preset number of the emission lens rows, eachemission lens of the lens groups has the lens vertices positioned so asto illuminate any of the illumination ranges; and a number of firstincident lenses in the lens group of the first incident lenses is equalto a number of first emission lenses in the lens group of the firstemission lenses, and a number of second incident lenses in the lensgroup of the second incident lenses is equal to a number of secondemission lenses in the lens group of the second emission lenses.
 5. Thefly-eye lens according to claim 3, wherein: the incident lens assemblagecomprises: a first incident lens group and a second incident lens groupthat are adjacent in the vertical direction, wherein the first incidentlens group comprises one or more first incident lens rows that areadjacent in the vertical direction, each of the one or more firstincident lens rows comprising a plurality of the first incident lensesthat are aligned in the horizontal direction, and wherein the secondincident lens group comprises one or more second incident lens rows thatare adjacent in the vertical direction, each of the one or more secondincident lens rows comprising a plurality of the second incident lensesthat are aligned in the horizontal direction, the emission lensassemblage comprises: a first emission lens group and a second emissionlens group that are adjacent in the vertical direction, wherein thefirst emission lens group comprises one or more first emission lens rowsthat are adjacent in the vertical direction, each of the one or morefirst emission lens rows comprising a plurality of the first emissionlenses that are aligned in the horizontal direction, and wherein thesecond emission lens group comprises one or more second emission lensrows that are adjacent in the vertical direction, each of the one ormore second emission lens rows comprising a plurality of the secondemission lenses that are aligned in the horizontal direction; a verticallens width of the first incident lenses in the first incident lens groupis different than a vertical lens width of the second incident lenses inthe second incident lens group; (i) vertical lens widths of the secondemission lenses in the second emission lens group are the same, or (ii)vertical lens widths of both the first emission lenses in the firstemission lens group and the second emission lenses in the secondemission lens group are the same; and a number of lens groups formed bythe first incident lenses is the same as a number of lens groups formedby the first emission lenses, and a number of lens groups formed by thesecond incident lenses is the same as a number of lens groups formed bythe second emission lenses.
 6. The fly-eye lens according to claim 4,wherein: the incident lens assemblage has the lens group of the firstincident lens disposed on each of an upper side and a lower side withreference to the group of the second incident lenses in the verticaldirection; and the emission lens assemblage has the lens group of thefirst emission lenses disposed on each of an upper side and a lower sidewith reference to the second emission lens in the vertical direction. 7.The fly-eye lens according to claim 4, wherein: the incident lensassemblage has the lens group of the second incident lenses disposed oneach of an upper side and a lower side with reference to the group ofthe first incident lenses; and the emission lens assemblage has the lensgroup of the second emission lenses disposed on each of an upper sideand a lower side with reference to the group of the first emissionlenses.
 8. The fly-eye lens according to claim 4, wherein: the lensgroups of the second incident lenses aligned in the vertical directionis greater in number than the lens groups of the first incident lenses;and the lens groups of the second emission lenses aligned in thevertical direction is greater in number than the lens groups of thefirst emission lenses.
 9. The fly-eye lens according to claim 4,wherein: among a plurality of lens groups of the second incident lensesaligned in the vertical direction, at least one lens group is differentin number of lens rows from other lens groups; among a plurality of lensgroups of the second emission lenses aligned in the vertical direction,at least one lens group is different in number of lens rows from otherlens groups; and the group of the second incident lenses and the groupof the second emission lenses differing in the number of lens rows areoptically opposed to each other, and the same as each other in thedifference in the number of the lens rows.
 10. The fly-eye lensaccording to claim 3, wherein lens vertices of the second emissionlenses are eccentrically positioned such that the second illuminationregion has vertical symmetry with respect to a center of the firstillumination region.
 11. The fly-eye lens according to claim 3, whereinlens vertices of the second emission lenses emitting light in the secondillumination region are eccentrically positioned so as to attain a lightillumination intensity distribution of the second illumination region inwhich a light illumination intensity is higher around a center and lowertoward a periphery of the whole second illumination region.
 12. Thefly-eye lens according to claim 3, wherein: in the incident lensassemblage, a shape of a lens surface obtained by connecting lensvertices of the first incident lenses and the second incident lenses isparallel to the horizontal direction and one of a concave surface and aconvex surface in the vertical direction; and in the emission lensassemblage, the first emission lenses and the second emission lenses areconnected to each other to form a curved surface substantially parallelto the incident lens assemblage.
 13. The fly-eye lens according to claim3, wherein: lens vertices of the first emission lenses are eccentricallypositioned such that a preset light illumination intensity distributionis attained in the first illumination region by the first emissionlenses emitting light in different illumination ranges in the firstillumination region for each lens row; and lens vertices of the secondemission lenses are eccentrically positioned such that a preset lightillumination intensity distribution is attained in the secondillumination region by the second emission lenses emitting light indifferent illumination ranges in the second illumination region for eachlens row.
 14. The fly-eye lens according to claim 3, wherein: lensvertices of the first emission lenses are eccentrically positioned so asto emit light in the first illumination region for each section in thehorizontal direction for each aligned lens row; and lens vertices of thesecond emission lenses are eccentrically positioned so as to emit lightin the second illumination region for each section in the horizontaldirection for each aligned lens row.
 15. The fly-eye lens according toclaim 3, wherein lens vertices in the lens rows of the emission lens areeccentrically positioned such that, in the first illumination region orin the second illumination region, the first illumination region or thesecond illumination region is formed by a group of illumination rangesthat become greater in the horizontal direction toward a lens surfacecenter in the vertical direction.
 16. The fly-eye lens according toclaim 3, wherein: the first illumination region is formed of, in a wholeillumination region being set, a group of regions illuminated atdifferent locations with light emitted from rows of the first emissionlenses, which regions are the same as one another in a vertical regionsize and differ from one another in a horizontal region size; and thesecond illumination region is formed of, in the whole illuminationregion, a group of regions being illuminated at different locations withlight emitted from rows of the second emission lenses, which regionsdiffer from one another in the vertical region size and the same as oneanother in the horizontal region size.
 17. The fly-eye lens according toclaim 3, wherein: the first illumination region is formed of, in a wholeillumination region being set, a group of regions being illuminated atdifferent locations with light emitted from rows of the first emissionlenses, which regions are the same as one another in a vertical regionsize and a horizontal region size; and the second illumination region isformed of, in the whole illumination region being set, a group ofregions being illuminated at different locations with light emitted fromrows of the second emission lenses, which regions are the same in thevertical region size and the horizontal region size.
 18. A fly-eye lenscomprising: an incident lens assemblage comprising a plurality of firstincident lenses that have a quadrangular shape and a plurality of secondincident lenses that have a quadrangular shape, wherein a horizontallens width of the second incident lenses is the same as a horizontallens width of the first incident lenses, wherein a vertical lens widthof the second incident lenses is smaller than a vertical lens width ofthe first incident lenses, and wherein the first incident lenses and thesecond incident lenses are aligned in a vertical direction and ahorizontal direction with their horizontal lens widths being the same ina vertical column; and an emission lens assemblage comprising aplurality of first emission lenses that have a quadrangular shape andthat are optically opposed to the first incident lenses, and a pluralityof second emission lenses that have a quadrangular shape and that areoptically opposed to the second incident lenses, the first emissionlenses and the second emission lenses being aligned in the verticaldirection and the horizontal direction with their horizontal lens widthbeing the same in a vertical column; wherein a dimension of thequadrangular shape of first incident lenses is set such that, on anilluminated surface, a preset first illumination region is attained, andwherein lens vertices of the first incident lenses are positioned suchthat light supplied by the first incident lenses to the first emissionlenses is optically opposed to the first incident lenses; wherein adimension of the quadrangular shape of the second incident lenses is setsuch that a preset second illumination region is obtained, an area ofthe second illumination region being smaller than an area of the firstillumination region, and the second illumination region being at leastpartially overlapped on the first illumination region on the illuminatedsurface, and wherein lens vertices of the second incident lenses arepositioned such that light supplied by the second incident lenses to thesecond emission lenses is optically opposed to the second incidentlenses; wherein a dimension of the quadrangular shape of the firstemission lenses is set and lens vertices of the first emission lensesare eccentrically positioned so as to emit light in the firstillumination region; and a dimension of the quadrangular shape of thesecond emission lenses is set and lens vertices of the second emissionlenses are positioned so as to emit light in the second illuminationregion.
 19. An illumination optical device comprising: a first opticalmember disposed in an optical path from a light source and configured toconvert light from the light source to a substantially collimated lightbeam; a fly-eye lens according to claim 18, which is configured toreceive light from the first optical member and emit the light with agray scale distribution; a second optical member disposed in an opticalpath of the light from the fly-eye lens; a light modulation deviceconfigured to receive light from the second optical member and emit thelight with its optical path changed; and a projection lens configured toproject the light from the light modulation device.
 20. The illuminationoptical device according to claim 19, wherein the light source is alight emitting diode or a laser diode.
 21. The illumination opticaldevice according to claim 19, wherein the first optical member is acollimating lens configured to convert light from the light source to acollimated light beam.
 22. The illumination optical device according toclaim 19, wherein the first optical member is a reflecting mirrorconfigured to reflect light from the light source to be a collimatedlight beam.